In this study we will attempt to clarify the role of axoplasmic transport in the pathogenesis of diabetic peripheral neuropathy. Studies will be done on the spontaneously diabetic "BB" Wistar rat in order to accurately simulate the human condition. A combined physiologic-morphologic approach will include sequential examination of: motor nerve conduction velocities, histologic and morphometric evaluation of sensory, motor and autonomic nerves, fast axoplasmic transport comparing precursors of proteins (3H-leucine) and glycoproteins (3H-fucose) and the distal turn-around of labelled proteins using retrograde axoplasmic transport. All findings will be correlated with blood glucose levels. These studies will be performed in a group of untreated rats, a group with marked hyperglycemia and one with mild hyperglycemia.